Managing Biological Width Around Dental Implants

Biological width is a term borrowed from periodontics, where it describes the band of soft tissue attachment that sits between the base of the gum sulcus and the crest of the bone around a natural tooth. It is roughly two millimetres, it is remarkably consistent between individuals, and the body defends it — place a restoration margin into that zone and the tissue will inflame and the bone will recede until the space is re-established.

Around an implant, the same principle applies but the structure is materially different. Understanding how it differs explains several decisions that otherwise look arbitrary: why implants are placed at a particular depth, why abutments are ideally not repeatedly removed and replaced, and why the gum around an implant behaves differently from the gum around the tooth beside it.

For the equivalent around natural teeth, our article on biological width and dental crowns covers the periodontal version.

Around a natural tooth, the attachment has two components: a junctional epithelium adhering to the enamel or cementum, and a connective tissue attachment in which collagen fibres insert into the cementum, running perpendicular to the root surface. Those inserting fibres are a mechanical anchor and an effective barrier.

Around an implant, there is no cementum and no periodontal ligament, so nothing for fibres to insert into. The connective tissue collagen runs parallel to the implant or abutment surface rather than perpendicular into it. The result is an adhesion rather than an attachment — a cuff of tissue resting against the titanium or ceramic rather than anchored in it.

Three further differences follow:

The seal is taller. The combined epithelial and connective tissue dimension around an implant is typically around three to four millimetres, compared with roughly two around a tooth. The body appears to require more tissue to achieve an equivalent barrier.

It is less vascular. The periodontal ligament supplies a substantial part of the blood supply to the tissue around a natural tooth. Implants have no ligament, so the peri-implant tissue is supplied only from the bone and the surrounding gum. Less vascularity means a reduced inflammatory and reparative response.

There is no ligament to absorb load or detect it. The periodontal ligament cushions forces and provides fine proprioceptive feedback. Without it, load transmits directly to bone — the subject of our article on how implants transmit chewing pressure differently.

Taken together, these mean the peri-implant seal is a real but comparatively fragile barrier. Once it is breached, inflammation tends to progress towards bone more readily than it does around a tooth, which is the underlying reason peri-implantitis behaves as it does. Early signs of peri-implantitis covers what that looks like clinically.

Depth of placement. Because the seal requires more vertical tissue than a natural tooth does, the implant platform is usually placed slightly deeper relative to the bone crest and the intended gum margin. Place it too shallow and there is not enough room for the seal to establish without the restoration margin encroaching on it. Place it too deep and the restorative margin sits far subgingivally, which makes cement removal and cleaning difficult.

Three-dimensional position, not just depth. Too far towards the lip and the thin buccal plate resorbs, taking the gum with it and exposing metal. Too close to an adjacent tooth or implant and the bone between them cannot support the papilla. The available space governs the tissue that can be maintained, and it is decided at surgery rather than afterwards. How implant positioning errors show up later covers the functional consequences.

Platform switching. Using an abutment narrower than the implant platform moves the implant–abutment junction inwards, away from the bone crest. The micro-gap at that junction is a bacterial reservoir and a site of micromovement, and shifting it horizontally appears to reduce the crestal bone response. This is why many contemporary systems are designed this way.

Minimising abutment disconnection. Every time an abutment is removed and replaced, the adhering soft tissue cuff is disrupted and has to re-form, usually slightly more apically each time. The principle of fitting the definitive abutment once and leaving it undisturbed follows directly from the fact that the seal is an adhesion rather than an anchored attachment.

Abutment material and surface. The soft tissue cuff adheres better to some surfaces than others. Highly polished titanium and zirconia in the transmucosal region support tissue adhesion and resist plaque; rough or contaminated surfaces do not.

Emergence profile. The shape of the crown as it emerges from the tissue determines whether the cuff is supported or compressed. An over-contoured crown compresses the tissue and creates an area that cannot be cleaned; an under-contoured one leaves the papilla unsupported. See implant crown design and long-term maintenance.

Cement control. Excess cement forced into the peri-implant sulcus is a well-documented cause of inflammation and bone loss, and it is difficult to detect and remove once the margin is deep. This is a substantial part of the argument for screw-retained restorations where the access position allows.

Two tissue characteristics influence how well the seal holds up.

Vertical mucosal thickness. Where the tissue over the bone crest is thin at the time of placement, the body will often resorb bone to establish the vertical dimension it requires for the seal. Augmenting thin tissue at the time of surgery, or using a longer transmucosal component, can reduce that early bone remodelling.

Keratinised tissue width. A band of firm, attached keratinised gum around the implant makes brushing more comfortable and appears associated with less plaque accumulation and inflammation, particularly where cleaning is imperfect. Where it is absent, a soft tissue graft is sometimes considered. How gum shape affects implant results covers the aesthetic dimension.

The practical implications are shorter than the biology.

Cleaning matters more, not less. Because the seal is an adhesion rather than an anchored attachment, and because the tissue has a reduced defensive response, plaque left at an implant margin is less well tolerated than at a tooth. Our guide on cleaning an implant compared with a natural tooth covers technique.

Bleeding at an implant is not normal. Around a tooth, bleeding on brushing is common and reversible. Around an implant it should be reported, because peri-implant inflammation progresses more readily. Gum discomfort around an implant covers the range of causes.

Monitoring is measurement, not impression. Baseline probing depths and a baseline radiograph taken when the crown is fitted are what later readings are compared against. Without a baseline, a four-millimetre probing depth means very little.

Recession around an implant does not recover. Unlike some periodontal recession, tissue lost around an implant rarely regenerates, and the result is exposed metal or a lengthening crown. This is why prevention is weighted so heavily.

Smoking and uncontrolled diabetes both impair it. Both reduce the vascular and immune response in tissue that already has less of both.

Is biological width the same around implants and teeth?

The principle is the same — the body defends a minimum soft tissue dimension between the sulcus and the bone. The structure differs: around an implant the collagen runs parallel rather than inserting, the dimension is larger, and the tissue is less vascular.

Why do dentists avoid removing and refitting implant abutments?

Each disconnection disrupts the soft tissue cuff adhering to the abutment, and it tends to re-form slightly lower each time. Fewer disconnections mean more stable tissue levels.

What is platform switching and does it matter?

It means using an abutment narrower than the implant platform, moving the implant–abutment junction inwards away from the bone. It appears to reduce crestal bone loss, though it is one factor among several.

Can the gum around my implant be improved after it has receded?

Sometimes, with soft tissue grafting or by modifying the restoration, but outcomes are less predictable than around natural teeth. Prevention is considerably more reliable than correction.

Does thin gum mean I cannot have an implant?

No. It means tissue thickness is part of the planning, and augmentation at the time of surgery may be discussed. Bone quality considerations covers the hard tissue equivalent.

If you have an implant and have noticed bleeding, tenderness or a change in gum level around it, an assessment with probing measurements and a radiograph is the appropriate next step.

You can contact our team at our Wimpole Street practice. Our dental implants page explains how treatment is planned here.

This article provides general information about peri-implant soft tissue and does not constitute individual dental advice. Implant planning, tissue assessment and the management of peri-implant inflammation require clinical examination and appropriate imaging. Wimpole Dental is regulated by the Care Quality Commission, and our clinicians are registered with the General Dental Council.

Next review due: 12 August 2027